Database migrations have always been complex, time-consuming, and costly due to proprietary data structures and data types, SQL extensions, and procedural languages. It can take up to several months to migrate a database, depending on database size, complexity, and usage of these proprietary features. A new technology has recently emerged for solving this problem: the database compatibility layer[DCL], a database access layer that supports another database management system's (DBMS's) proprietary extensions natively, allowing existing applications to access the new database transparently.